add cron job to foreground

Question

I am trying to run a program that pops up a graphical notice to me. As a simple example, I have my cron settings as

@hourly xlogo

and if I launch xlogo from an interactive command, it works fine. However, when run by cron, the xlogo window never launches. How can I get cron to let xlogo launch a window, or is it just fundamentally not designed to do that?

Answer 1

It is totally possible to do this with crontab.

You need to tell the script which screen you want xlogo to run on.

Try changing the line to this:

@hourly /usr/bin/env DISPLAY=:0.0 /usr/bin/xlogo

to tell crontab what display you want it to use. Depending on the program you might need to add in more enviornment variables as well.

Answer 2

You need to tell it which display to use with the export command. I also would recommend always using the full path to a file with cron. It will save you a lot of headaches, as cron runs in a limited environment, so it doesn't always have the same $PATH variable as your terminal. This means it doesn't always know where programs are located.

At any rate, your cron job would look something like this:

@hourly export DISPLAY=:0.0 && /usr/bin/xlogo